import {  DEFAULT_PROVIDER_HEALTH_REFRESH_INTERVAL,  type ServerProvider,  ServerSettingsError,} from "@t3tools/contracts";import { resolveServerBackgroundActivitySettings } from "@t3tools/shared/backgroundActivitySettings";import * as Duration from "effect/Duration";import * as Effect from "effect/Effect";import * as Equal from "effect/Equal";import * as Fiber from "effect/Fiber";import * as PubSub from "effect/PubSub";import * as Queue from "effect/Queue";import * as Ref from "effect/Ref";import * as Scope from "effect/Scope";import * as Stream from "effect/Stream";import * as Semaphore from "effect/Semaphore"; import * as BackgroundPolicy from "../background/BackgroundPolicy.ts";import { ServerSettingsService } from "../serverSettings.ts";import { applyUsageLimitsUpdate, resolveUsageLimitsAfterProbe } from "./providerUsageLimits.ts";import type { ServerProviderShape } from "./Services/ServerProvider.ts"; interface ProviderSnapshotState {  readonly snapshot: ServerProvider;  readonly enrichmentGeneration: number;} function withUsageLimits(  snapshot: ServerProvider,  usageLimits: ServerProvider["usageLimits"],): ServerProvider {  if (snapshot.usageLimits === usageLimits) {    return snapshot;  }  const { usageLimits: _previous, ...rest } = snapshot;  return usageLimits ? { ...rest, usageLimits } : rest;} export const makeManagedServerProvider = Effect.fn("makeManagedServerProvider")(function* <  Settings,>(input: {  readonly resolveMaintenance: ServerProviderShape["resolveMaintenance"];  readonly getSettings: Effect.Effect<Settings, ServerSettingsError>;  readonly streamSettings: Stream.Stream<Settings>;  readonly haveSettingsChanged: (previous: Settings, next: Settings) => boolean;  readonly initialSnapshot: (settings: Settings) => Effect.Effect<ServerProvider>;  readonly checkProvider: Effect.Effect<ServerProvider, ServerSettingsError>;  readonly enrichSnapshot?: (input: {    readonly settings: Settings;    readonly snapshot: ServerProvider;    readonly getSnapshot: Effect.Effect<ServerProvider>;    readonly publishSnapshot: (snapshot: ServerProvider) => Effect.Effect<void>;  }) => Effect.Effect<void>;  readonly refreshInterval?: Duration.Input;  readonly refreshOnInterval?: boolean;  readonly checkProviderOnSettingsChange?: (previous: Settings, next: Settings) => boolean;}): Effect.fn.Return<  ServerProviderShape,  ServerSettingsError,  Scope.Scope | BackgroundPolicy.BackgroundPolicy | ServerSettingsService> {  const backgroundPolicy = yield* BackgroundPolicy.BackgroundPolicy;  const serverSettings = yield* ServerSettingsService;  const refreshSemaphore = yield* Semaphore.make(1);  const changesPubSub = yield* Effect.acquireRelease(    PubSub.unbounded<ServerProvider>(),    PubSub.shutdown,  );  const initialSettings = yield* input.getSettings;  const initialSnapshot = yield* input.initialSnapshot(initialSettings);  const snapshotStateRef = yield* Ref.make<ProviderSnapshotState>({    snapshot: initialSnapshot,    enrichmentGeneration: 0,  });  const settingsRef = yield* Ref.make(initialSettings);  const enrichmentFiberRef = yield* Ref.make<Fiber.Fiber<void, unknown> | null>(null);  const scope = yield* Effect.scope;   const publishEnrichedSnapshot = Effect.fn("publishEnrichedSnapshot")(function* (    generation: number,    nextSnapshot: ServerProvider,  ) {    const snapshotToPublish = yield* Ref.modify(snapshotStateRef, (state) => {      if (state.enrichmentGeneration !== generation) {        return [null, state] as const;      }      // Enrichment derives from the snapshot it was handed; a runtime usage      // update that landed since must not be reverted by it.      const merged = withUsageLimits(nextSnapshot, state.snapshot.usageLimits);      if (Equal.equals(state.snapshot, merged)) {        return [null, state] as const;      }      return [merged, { ...state, snapshot: merged }] as const;    });    if (snapshotToPublish === null) {      return;    }    yield* PubSub.publish(changesPubSub, snapshotToPublish);  });   const restartSnapshotEnrichment = Effect.fn("restartSnapshotEnrichment")(function* (    settings: Settings,    snapshot: ServerProvider,    generation: number,  ) {    const previousFiber = yield* Ref.getAndSet(enrichmentFiberRef, null);    if (previousFiber) {      yield* Fiber.interrupt(previousFiber).pipe(Effect.ignore);    }     if (!input.enrichSnapshot) {      return;    }     const fiber = yield* input      .enrichSnapshot({        settings,        snapshot,        getSnapshot: Ref.get(snapshotStateRef).pipe(Effect.map((state) => state.snapshot)),        publishSnapshot: (nextSnapshot) => publishEnrichedSnapshot(generation, nextSnapshot),      })      .pipe(Effect.ignoreCause({ log: true }), Effect.forkIn(scope));     yield* Ref.set(enrichmentFiberRef, fiber);  });   const applySnapshotBase = Effect.fn("applySnapshot")(function* (    nextSettings: Settings,    options?: { readonly forceRefresh?: boolean },  ) {    const forceRefresh = options?.forceRefresh === true;    const previousSettings = yield* Ref.get(settingsRef);    if (!forceRefresh && !input.haveSettingsChanged(previousSettings, nextSettings)) {      yield* Ref.set(settingsRef, nextSettings);      return yield* Ref.get(snapshotStateRef).pipe(Effect.map((state) => state.snapshot));    }     if (      !forceRefresh &&      input.checkProviderOnSettingsChange?.(previousSettings, nextSettings) === false    ) {      const state = yield* Ref.get(snapshotStateRef);      const nextGeneration = state.enrichmentGeneration + 1;      yield* Ref.set(snapshotStateRef, {        ...state,        enrichmentGeneration: nextGeneration,      });      yield* Ref.set(settingsRef, nextSettings);      yield* restartSnapshotEnrichment(nextSettings, state.snapshot, nextGeneration);      return state.snapshot;    }     const probedSnapshot = yield* input.checkProvider;    const { snapshot: nextSnapshot, generation: nextGeneration } = yield* Ref.modify(      snapshotStateRef,      (state) => {        const generation = input.enrichSnapshot          ? state.enrichmentGeneration + 1          : state.enrichmentGeneration;        const snapshot = withUsageLimits(          probedSnapshot,          resolveUsageLimitsAfterProbe({            published: state.snapshot.usageLimits,            probed: probedSnapshot.usageLimits,          }),        );        return [          { snapshot, generation },          { snapshot, enrichmentGeneration: generation },        ] as const;      },    );    yield* Ref.set(settingsRef, nextSettings);    yield* PubSub.publish(changesPubSub, nextSnapshot);    yield* restartSnapshotEnrichment(nextSettings, nextSnapshot, nextGeneration);    return nextSnapshot;  });  const applySnapshot = (nextSettings: Settings, options?: { readonly forceRefresh?: boolean }) =>    refreshSemaphore.withPermits(1)(applySnapshotBase(nextSettings, options));   /**   * Runtime usage updates arrive between probes. They patch only   * `usageLimits` on whatever snapshot is published and leave the enrichment   * generation alone, so an in-flight enrichment still lands.   */  const applyUsageLimits: ServerProviderShape["applyUsageLimits"] = (update) =>    Effect.gen(function* () {      const snapshotToPublish = yield* Ref.modify(snapshotStateRef, (state) => {        const usageLimits = applyUsageLimitsUpdate({          previous: state.snapshot.usageLimits,          update,          checkedAt: update.checkedAt,        });        // `applyUsageLimitsUpdate` hands back the same object when nothing        // moved, which is the common case for Codex's per-tick notification.        if (usageLimits === state.snapshot.usageLimits) {          return [null, state] as const;        }        const snapshot = withUsageLimits(state.snapshot, usageLimits);        return [snapshot, { ...state, snapshot }] as const;      });      if (snapshotToPublish !== null) {        yield* PubSub.publish(changesPubSub, snapshotToPublish);      }    });   const refreshSnapshot = Effect.fn("refreshSnapshot")(function* () {    const nextSettings = yield* input.getSettings;    return yield* applySnapshot(nextSettings, { forceRefresh: true });  });   const hasProviderStatusDemand = Effect.gen(function* () {    const state = yield* Ref.get(snapshotStateRef);    const instanceId = state.snapshot.instanceId;    const [genericDemand, instanceDemand] = yield* Effect.all([      backgroundPolicy.shouldRunScopeWork({ type: "provider-status" }),      backgroundPolicy.shouldRunScopeWork({ type: "provider-status", instanceId }),    ]);    return genericDemand || instanceDemand;  });   const getRefreshInterval =    input.refreshInterval !== undefined      ? Effect.succeed(input.refreshInterval)      : serverSettings.getSettings.pipe(          Effect.map(            (settings) =>              resolveServerBackgroundActivitySettings(settings).providerHealthRefreshInterval,          ),          Effect.orElseSucceed(() => DEFAULT_PROVIDER_HEALTH_REFRESH_INTERVAL),        );   const refreshIntervalChanges = yield* Queue.sliding<void>(1);  if (input.refreshInterval === undefined) {    const serverSettingsChanges = yield* serverSettings.subscribeChanges;    yield* serverSettingsChanges.pipe(      Stream.map((settings) =>        Duration.toMillis(          resolveServerBackgroundActivitySettings(settings).providerHealthRefreshInterval,        ),      ),      Stream.changes,      Stream.runForEach(() => Queue.offer(refreshIntervalChanges, undefined).pipe(Effect.asVoid)),      Effect.forkScoped,    );  }   yield* Stream.runForEach(input.streamSettings, (nextSettings) =>    Effect.asVoid(applySnapshot(nextSettings)),  ).pipe(Effect.forkScoped);   yield* Effect.forever(    getRefreshInterval.pipe(      Effect.flatMap((refreshInterval) =>        Effect.raceFirst(          Effect.sleep(            Duration.toMillis(Duration.fromInputUnsafe(refreshInterval)) <= 0              ? "60 seconds"              : refreshInterval,          ).pipe(Effect.as(true)),          Queue.take(refreshIntervalChanges).pipe(Effect.as(false)),        ).pipe(          Effect.flatMap((intervalElapsed) =>            input.refreshOnInterval !== false &&            intervalElapsed &&            Duration.toMillis(Duration.fromInputUnsafe(refreshInterval)) > 0              ? hasProviderStatusDemand.pipe(                  Effect.flatMap((shouldRefresh) =>                    shouldRefresh ? refreshSnapshot().pipe(Effect.asVoid) : Effect.void,                  ),                )              : Effect.void,          ),        ),      ),      Effect.ignoreCause({ log: true }),    ),  ).pipe(Effect.forkScoped);   yield* applySnapshot(initialSettings, { forceRefresh: true }).pipe(    Effect.ignoreCause({ log: true }),    Effect.forkScoped,  );   return {    resolveMaintenance: input.resolveMaintenance,    getSnapshot: Ref.get(snapshotStateRef).pipe(Effect.map((state) => state.snapshot)),    refresh: refreshSnapshot().pipe(Effect.tapError(Effect.logError), Effect.orDie),    applyUsageLimits,    get streamChanges() {      return Stream.fromPubSub(changesPubSub);    },  } satisfies ServerProviderShape;});